Particle-in-Molybdenum Disulfide-Coated Cavity Structure with a Raman Internal Standard for Sensitive Raman Detection of Water Contaminants from Ions to <300 nm Nanoplastics

Abstract

To develop a universal and precise detection strategy that can be applied to water contaminants of various sizes, we designed a particle-in-MoS 2 coated cavity structure of AAO/MoS 2 /Ag with a Raman internal standard. This modified particle-in-cavity structure not only successfully integrates both "surface hot spots" and "volume hot spots" via dressing and manipulating the cascaded optical-field mode inside the cavity but also introduces the chemical enhancement and internal standard attribute of MoS 2 . Because of its unique three-dimensional structure, AAO/MoS 2 /Ag accurately detects water contaminants of various sizes from ions to nanoplastics (<300 nm) for the first time. This work proposes a novel and universal surfaceenhanced Raman scattering strategy for detecting multiple-size water contaminants and demonstrates the potential to build a security line in early warning systems for the prevention of water pollution.

Machine Learning‐Driven 3D Plasmonic Cavity‐in‐Cavity Surface‐Enhanced Raman Scattering Platform with Triple Synergistic Enhancement Toward Label‐Free Detection of Antibiotics in Milk

“…It has been demonstrated that such AAO dimensions help achieve better light utilization in the nearinfrared region. [49,50] The physical images of the large-scale 3D CIC SERS substrate preparation process are shown in Figure 3A-D. The CIC SERS substrates were prepared by transferring monolayers of Au TCNCs on the surface of 2 cm long AAO templates (Figure 3C).…”

Strategies and Challenges of Identifying Nanoplastics in Environment by Surface-Enhanced Raman Spectroscopy

“…This study provides new ideas and tools for the detection of environmental nanoplastics. Li et al 110 also designed a SERS substrate similar to the Klarite structure, a 3D material based on a modified particle-in-cavity (PIC) structure, consisting of AAO conical pores, MoS 2 layers and Ag NPs, which has been used to characterize nanoplastics (<300 nm). The PIC structure integrates "surface hotspots" and "volume hotspots" and introduces the internal standard property of MoS 2 , its curved inverted cone facilitates the capture of nanoplastics and simultaneously achieves high SERS enhanced detection.…”

“…The enhancement region is limited to the nearby surface of the structure (∼1–10 nm), which limits the detection of particles of various sizes. , Nanoarray substrates with PIC structures combine a “volume hot spot” (inside the cavity) and a “surface hot spot” (on the surface of the nanostructure), extending the effective area of the conventional local electric field in SERS structures and facilitating the detection of particulate targets (Table ). Substrate stability and interference resistance. Impurities carried by SERS substrates are mainly introduced during the synthesis.…”

Surface-enhanced Raman scattering as a potential strategy for wearable flexible sensing and point-of-care testing non-invasive medical diagnosis

“…The high SERS sensitivity and uniformity are due to the efficient enhancement ability of porous 3D PIC structure and highly ordered periodic array ( Liu, et al, 2022 ; Wang, et al, 2022 ). As illustrated in Figure 1E , Li et al (2022) designed a quasi-periodic PIC Raman substrate structure based on silver nanoparticles and anodic alumina templates to achieve sensitive detection at the single-molecule level and further improved the detection accuracy by introducing molybdenum disulfide as an internal standard. With the advantages of local hot spots, spatial hot spots and high adsorption properties of PIC structure intrinsic, the AAO/MoS 2 /Ag 3D structure achieved sensitive detection of multi-size pollutants including heavy metal ions, small molecule pollutants, and nano plastics in the water.…”